package class10;

import java.util.Arrays;
import java.util.Comparator;

/**
 * @author zhangchaoliang
 * create 2022
 */
public class BestArrange {

    public static class Program{
        public int start;
        public int end;

        public Program(int start,int end){
            this.start = start;
            this.end = end;
        }
    }

    public static int bestArrange1(Program[] programs){
        if (programs == null || programs.length ==0)
            return 0;
        return process(programs,0,0);
    }

    public static int process(Program[] programs,int done,int timeLine){
        if (programs.length == 0){
            return done;
        }
        int max = done;
        for (int i=0;i <programs.length;i++){
           if (programs[i].start >= timeLine){
               Program[] next = copyButExcept(programs,i);
               max = Math.max(max,process(next,done+1,programs[i].end));
           }
        }
        return max;
    }

    public static Program[] copyButExcept(Program[] programs,int i){
        Program[] ans = new Program[programs.length-1];
        int index = 0;
        for (int l = 0; l<programs.length;l++){
            if (l != i)
                ans[index++] = programs[l];
        }
        return ans;
    }

    public static class ProgramComparator implements Comparator<Program>{

        @Override
        public int compare(Program o1, Program o2) {
            return o1.end - o2.end;
        }
    }

    public static int bestArrange2(Program[] programs){
        Arrays.sort(programs,new ProgramComparator());
        int timeLine = 0;
        int result = 0;

        for (int i=0;i<programs.length;i++){
            if (timeLine <= programs[i].start){
                result++;
                timeLine = programs[i].end;
            }
        }
        return result;
    }

    public static Program[] generatePrograms(int programSize,int timeMax){
        Program[] ans = new Program[(int)(Math.random()*(programSize+1))];
        for (int i=0;i<ans.length;i++){
            int r1 = (int)(Math.random()*(timeMax+1));
            int r2 = (int) (Math.random()*(timeMax+1));
            if (r1 == r2){
                ans[i] = new Program(r1,r1 + 1);
            }else {
                ans[i] = new Program(Math.min(r1,r2),Math.max(r1,r2));
            }
        }
        return ans;
    }

    public static void main(String[] args) {
        int programSize = 12;
        int timeMax = 20;
        int timeTimes = 100000;
        for (int i=0;i<timeTimes;i++){
            Program[] programs = generatePrograms(programSize,timeMax);
            if (bestArrange1(programs) != bestArrange2(programs))
                System.out.println("Oops!");
        }
        System.out.println("finish!");
    }
}
